Toxicology Commons^™

Cytotoxicity Of Copper (Ii) Octanoate On Mouse Hippocampal Astrocytes, Ali A. Shohatee

Theses and Dissertations

Copper, as an essential trace element, is crucial for various biological processes but has also been utilized as a constituent of various pesticides for decades. Copper (II) octanoate is a pesticide utilized as a fungicide and is approved for use in the production of certified organic foods. Previous studies have implicated copper as an inducer of oxidative stress and activator of the Nrf2-ARE pathway. Nrf2 is essential in regulating the transcription of various genes to alleviate toxicity such as those involved in glutathione synthesis and detoxification. Due to the limited toxicological data, this study into the potential induction of oxidative …

Growth And Survival Of Amphibians Exposed To Road Salt And Glyphosate-Based Herbicide, Jerica Eaton

Mahurin Honors College Capstone Experience/Thesis Projects

Amphibian populations are threatened by increasing levels of environmental pollution resulting from human activities. Areas with mixed land use that include agriculture and urban development experience increased contamination from surface herbicide and road deicer application. Upon entering water sources, these chemicals have the capacity to disrupt the natural dynamics of aquatic ecosystems. This study aimed to evaluate the effects of these contaminants on amphibian populations. I used the spotted salamander (Ambystoma maculatum) as a model, rearing larvae from hatching to metamorphosis. I subjected larvae in each of the treatment groups to varying levels of herbicide and salt concentrations. …

Hepatic Transcriptomic Assessment Of Sprague Dawley Rats In Response To Dietary Perfluorobutane Sulfonate (Pfbs) Ingestion, Isaac Appiah

College of Graduate Studies: Theses & Dissertations

Perfluorobutane sulfonate (PFBS) is a short-chain PFAS that is considered to be a less toxic replacement for the rather more toxic long-chain perfluorooctane sulfonate (PFOS). Its numerous industrial applications and widespread presence in the environment have raised environmental and health concerns because of growing evidence associating adverse health effects and certain liver diseases to PFBS exposure. The study goal was to investigate whether dietary ingestion of PFBS would induce liver injuries, damage, inflammations, and oxidative stress. To achieve these goals, Sprague-Dawley rats were assigned into three PFBS dietary treatment groups (0, 50, and 100 PPM) for 11 weeks. After this …

Trends In Cyanotoxin Production Potential In China Lake: An Edna Analysis Of Microcystis And Dolichospermum And The Environmental Drivers Of Cyanotoxin Production, Gennifer M. Rubin

Honors Theses

Episodes of cyano-harmful algal blooms (cyano-HABs) are hypothesized to be exacerbated by the effects of climate change. However, the dynamics of the interactions between elements of climate change and toxigenic cyanobacteria proliferation are not well defined. China Lake is the drinking water source for 7 municipalities in the Kennebec County and is one of many lakes in central Maine that has been subjected to high levels of cyano-HABs and microcystin toxin contamination in recent years. Monitoring the toxicity of these blooms in relation to various aspects of climate change may lead to identification of the major drivers of microcystin production …

Telomeres: A Tool To Assess The Impacts Of Mining Contaminants On Riparian Songbirds, Lillian Krach, Bridger Creel, Megan Fylling, Zac Cheviron, Creagh Breuner

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Mining has left massive environmental and physical scars across the landscape. Aquatic and riparian landscapes in particular have been significantly impacted by traditional mining practices. Waste products left over from hard-rock mining leech heavy metals onto the landscape and these metals spread from headwater streams to major waterways (Lottermoser 2010). Heavy metals have been shown to cause physiological stress and challenges to organisms depending on the metal and the concentration (Baos et al. 2019, Boyd & Rajakaruna 2013). While some mining-impaired areas have undergone restoration efforts, is it enough? Typical restoration methods replace the contaminated floodplain, but not the riverbed …

Examining The Oxidative Stress Effects In Rats Exposed To 2-Aminoanthracene In Utero And High Fat Diet Three Months After, Brianna A. Lanoix

Honors College Theses

Polycyclic aromatic hydrocarbons are organic compounds that are created synthetically or found in partially burned oil, gasoline, and coal. 2-aminoanthracene (2AA) is a common example of a PAH and can affect lipid and carbohydrate metabolism and resulting in inflammatory problems and oxidative stress. The objective of the research project is to investigate oxidative stress in relation to diabetes in rats exposed to 2AA in utero and a high fat diet later in life. Pregnant dams were separated into treatment groups based on their dosages of 2AA; 0 mg/kg (control), 50 mg/kg (low), 100 mg/kg (high). During the gestation -postpartum period, …

Inferring Exposure To Harmful Pseudo-Nitzschia Blooms From Ocean-To-Estuary Gradients In Domoic Acid Concentrations In Humboldt Bay Bivalves, Natasha Hope Ficzycz Winnacott

Cal Poly Humboldt theses and projects

Harmful algal blooms (HABs) result from outbreaks of any of several different species of toxin-producing phytoplankton and that can have major detrimental effects on marine ecosystems and pose severe health and economic threats to human communities. Of particular concern along the United States West Coast are HABs of pennate diatom genus Pseudo-nitzschia that produce the potent neurotoxin domoic acid (DA). The coastal ocean between Cape Mendocino, CA, and Cape Blanco, OR is a hotspot for Pseudo-nitzschia spp. HABs. Such blooms impact coastal fisheries and pose a potential threat to aquaculture operations in Humboldt Bay, California’s second largest estuary and largest …

Halogen Bonding Interactions Of Haloaromatic Endocrine Disruptors And The Potential For Inhibition Of Iodothyronine Deiodinases, Craig A. Bayse

Chemistry & Biochemistry Faculty Publications

Halogen bonding (XB) is a potential mechanism for the inhibition of the thyroid-activating/deactivating iodothyronine deiodinase family of selenoproteins through interactions with halogenated endocrine disrupting compounds (EDCs). Trends in XB interactions were examined using density functional theory for a series of polyhalogenated dibenzo-1,4-dioxins, biphenyls, and other EDCs with methylselenolate, a simple model of the Dio active site selenocysteine. The strengths of the interactions depend upon the halogen (Br>Cl), the degree of substitution, and the position of the acceptor. In terms of donor-acceptor energies, interactions at the meta position are often the strongest, suggesting a link to the topology of THs, …

Co-Occurrence Of Marine And Freshwater Phycotoxins In Oysters, And Analysis Of Possible Predictors For Management, Sarah K. D. Pease, Todd A. Egerton, Kimberly S. Reece, Marta P. Sanderson, Michelle D. Onofrio, Evan Yeargan, Adam Wood, Amanda Roach, I-Shuo Wade Huang, Gail P. Scott, Allen R. Place, Amy M. Hayes, Juliette L. Smith

Biological Sciences Faculty Publications

Oysters (Crassostrea virginica) were screened for 12 phycotoxins over two years in nearshore waters to collect baseline phycotoxin data and to determine prevalence of phycotoxin co-occurrence in the commercially and ecologically-relevant species. Trace to low concentrations of azaspiracid-1 and -2 (AZA1, AZA2), domoic acid (DA), okadaic acid (OA), and dinophysistoxin-1 (DTX1) were detected, orders of magnitude below seafood safety action levels. Microcystins (MCs), MC-RR and MC-YR, were also found in oysters (maximum: 7.12 μg MC-RR/kg shellfish meat wet weight), warranting consideration of developing action levels for freshwater phycotoxins in marine shellfish. Oysters contained phycotoxins that impair shellfish health: karlotoxin1-1 and …

Bioaccumulation Of Polychlorinated Biphenyl Compounds And Mercury In A Mining Impacted Aquatic Ecosystem, Michelle Bollini

Dissertations, Master's Theses and Master's Reports

The Keweenaw area continues to be influenced by the century of copper mining that ended nearly 50 years ago. This project is focused on Torch Lake, an aquatic ecosystem that has been heavily impacted by mining waste disposal. The watershed has been impaired by mine discharge and tailings, smelter and smokestack plumes, and poor waste disposal practices. The lake is listed as a Great Lakes Area of Concern with beneficial use impairments of restrictions on fish consumption and a degraded benthic community. Polychlorinated biphenyl compounds (PCBs) and methylmercury (MeHg) are persistent, bioaccumulative, and toxic substances (PBTs). These contaminants pose threats …

Assessment Of Spilled Toxic Bait By Wild Pigs And Potential Risk To Non-Target Species, John C. Kinsey, Justin A. Foster, Nathan P. Snow, Jason D. Wishart, Linton D. Staples, Janis K. Bush, Kurt V. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Background

In 2018, a sodium nitrite (SN)-based toxic bait for invasive wild pigs (hereafter wild pigs; Sus scrofa), was evaluated to determine its effectiveness in reducing local wild pig populations in Texas. Localized population reductions of > 70% were achieved, but spillage of bait outside wild pig-specific feeders (bait stations) caused by feeding wild pigs resulted in the deaths of non-target animals. To evaluate risks to non-target animals, we tested whether bait presentation influenced the total amount of bait spilled by wild pigs and estimated the associated risk to non-target species.

Results

We found that bait spilled outside bait stations …

Revisiting The 2018 Corsica Oil Spill - A Preliminary Case Study Of Ecosystem Recovery From Pahs In Yelkouan Shearwater (Puffinus Yelkouan), Makenna Mahrer

CMC Senior Theses

Polycyclic aromatic hydrocarbons (PAHs) are a specific class of persistent organic pollutants (POPs) heavily associated with crude oil, and pose genotoxic and physiological threats to marine life when released into the aquatic environment during a petroleum spill. This study seeks to understand the residual impacts of the 2018 Corsica oil spill on Puffinus yelkouan (Yelkouan Shearwater), a seabird endemic to the Mediterranean basin, using the species as a bioindicator for contamination in the region. Though classified by the IUCN Red List as ‘vulnerable,’ this species remains grossly understudied in present monitoring literature. This study made use of blood samples and …

Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry Quantitation Of O-Cresol In Hydrolyzed Human Urine To Assess Toluene Exposure, Eric Langlois, Sébastien Gagné

Études primaires

Rationale

Toluene is a volatile organic compound used in domestic and industrial applications. The main routes of workplace exposure to toluene are inhalation and dermal contact. As toluene exposure can cause severe nervous system damage, its quantification is crucial to prevent occupational illness. Toluene is metabolized mainly as hippuric acid, S-benzylmercapturic acid and epoxides. These are rapidly converted to o-/p-cresol, which is then excreted in the urine as conjugated glucuronides and sulfates. o-Cresol and its conjugates can be chemically hydrolyzed to form free o-cresol, which can then serve as a urinary biomarker of toluene exposure. Current …

Gut-Lung Axis Of The Microbiome Alterations After Ultrafine Particles And Ozone Inhalation, Md Habibul Hasan Mazumder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Air pollution poses a significant threat to public health. It is a mixture of particulate matter, gaseous substances, and other secondary substances. Despite epidemiological research indicating the interactive effects of various components of air pollution, existing studies and regulatory limits often focus on single-exposure scenarios. The emerging understanding of the microbiome’s role in regulating immune response, metabolism, and pathophysiology of various diseases points towards interactions between environmental exposures and microbial dysbiosis. In this dissertation, mice were exposed to relevant deposited doses of carbon black (CB) and ozone (O3), and lung inflammation as well as the lung-gut axis of the microbiome …

Promoting Healthier Treatment Outcomes In Obese Cancer Patients Taking High Dose Methotrexate, Carly Dell'ova

Walden Dissertations and Doctoral Studies

Cancer and obesity rates continue to rise, creating enormous public heath burdens to the individual and at the national and global levels, reducing quality of life, and increasing spending. Moreover, the relationships between cancer and obesity are not well understood. A commonly used chemotherapy for several types of cancer is high dose methotrexate (HDMTX). Along with chemotherapy, especially at high doses, comes toxicity to specific organs and the entire body. However, limited research has been conducted on obese cancer patients as they are often excluded from clinical studies. Practitioners need to better understand how to dose these patients to provide …

Acute Copper (Cu) Toxicity In Dragonfly Naiads (Insecta: Odonata), Jeff M. Simpson

Department of Entomology: Distance Master of Science Projects

The objective of this study was to examine the effects copper (Cu) on mortality within a pair of test groups of naiads in the order Odonata, and to replicate previous observations regarding their potential uses as indicators for water quality. Few past studies have examined toxicity within relation to the odonates. It has been suggested that this order may contain valuable model organisms (Tollett et al., 2008). Very little focus has been given to odonates as bioindicators, with the few studies done being performed on species that would typically inhabit lentic environments (Trevino, 1999). Similarly, the test subjects for this …

Characterizing The Effects Of Antiandrogens And Senolytics To Enhance The Therapeutic Response To Castration-Resistant Prostate Cancer, Justin M. Silverman

Theses and Dissertations

Prostate cancer is the most frequently diagnosed cancer in males and the second most common cause of cancer deaths. Androgen deprivation therapy, whether through surgical or chemical castration, is the mainstay for treatment of advanced prostate cancer; however, despite an initial response, most patients eventually develop a progressive PSA rise, and castration- sensitive prostate cancer gives rise to castration-resistant prostate cancer. The standard of care therapy includes the antiandrogens such as enzalutamide and abiraterone acetate as well as the microtubule poison, docetaxel, and various immunotherapies; however, while prostate cancer research is progressing, there continues to be a compelling need for …

Quantification Of Phosphatidylethanol In Whole Blood And Dried Blood Spots By Lc-Ms/Ms, Elizabeth Yulianto

Student Theses

Phosphatidylethanol (PEth) is an alcohol biomarker that provides a longer window of detection than direct alcohol measurement or other common alcohol metabolites, like ethyl glucuronide. PEth has become useful in assessing drinking history, such as for alcohol-withdrawal treatment, organ transplant settings or prenatal alcohol exposure determination. A method was developed and validated to quantify PEth 16:0/18:1 and 16:0/18:2 in whole blood and dried blood spots (DBS) by liquid chromatography tandem mass spectrometry (LC-MS/MS). The whole blood method was applied to 149 samples from pregnant women, elucidating possible prenatal alcohol exposure. Fifty μL whole blood and 12.7 mm whole punches from …

Inhibition Of Rad18 By Arsenic, Lindsay B. Volk

Biomedical Sciences ETDs

Arsenite exposure leads to the retention of UV-induced DNA damage, thus burdening translesion synthesis (TLS). Rad18 is an essential factor in initiating TLS through PCNA monoubiquitination and is implicated in homologous recombination. It contains two functionally and structurally distinct zinc fingers that are potential targets for arsenite binding. Results from this study reveal arsenite binding to both zinc fingers of Rad18 and a corresponding loss of domain function. Importantly, arsenite inhibited Rad18 RING-dependent PCNA monoubiquitination and polymerase eta recruitment to DNA damage. Further analysis demonstrated multiple effects of arsenite, including the reduction in the nuclear localization and UV-induced chromatin recruitment …

Hepatocyte-Hepatic Stellate Cell Axis In Potentiation Of Alcohol And Hiv-Induced Liver Injury, Moses O. New-Aaron

Theses & Dissertations

Human Immunodeficiency Virus (HIV) remains a global threat, with approximately 38.4 million active infections and 33 million HIV-related deaths since the first case. While many may be tempted to think of HIV as a relic of the past, emerging data suggests otherwise. By the end of 2021, approximately 1.5 million HIV incidences and 650 000 mortalities were reported globally. The etiologies of HIV-related mortality are numerous. Liver disease is one of the leading etiologies of HIV-related mortality, especially in recent times of antiretroviral therapy (ART)-induced longevity among people living with HIV (PLWH). While co-infections with hepatotropic viruses notoriously contribute to …